Motor/fan assembly having a radial diffuser bypass

ABSTRACT

A bypass motor assembly includes a motor having a rotatable shaft, a working air fan secured to the rotatable shaft and a shroud having an intake eyelet and at least one exhaust apertures. The assembly includes an end bracket having a shaft hole through which the shaft extends. The end bracket and the shroud partially enclose the working air fan, wherein rotation of the working air fan draws air in through the intake eyelet and pushes the air through the plurality of exhaust apertures, the end bracket having a plurality of vanes that form a fan chamber that receives the working air fan such that air expelled by the working air fan is efficiently re-directed by the vanes toward the exhaust aperture. An air intake seal can be disposed between the shroud and the working air fan to further enhance the working air flow.

TECHNICAL FIELD

The invention herein resides in the art of dynamoelectric machines and,more particularly, in the art of bypass motor/fan assemblies.Particularly, the invention relates to a bypass motor assembly in whichthe working air is provided with a laminar outward and downward exhaustflow path, greatly increasing the efficiency of the assembly. An airintake seal is also provided to improve the assembly's efficiency.

BACKGROUND ART

Presently, many pieces of cleaning equipment are subjected to water ormoisture. Particularly, wet/dry vacuum cleaners such as those known asutility vacs and carpet extractors operate in an environment in whichthe debris which is extracted from the surface being cleaned is laden ina mixture of air and water. In order to prevent the moisture laden airfrom entering the vacuum generating motor, bypass motors are typicallyused in these operations. As is known to those skilled in the art, abypass motor/fan assembly is one in which the working air, generated bya working air fan, never passes through the motor, but is totallyisolated from the motor. The motor itself may have a separate motorcooling air fan which draws cooling air over the motor armature andfield. Accordingly, the working air and the motor cooling air taketotally separate paths, and do not mix—except possibly in an exhaustarea. While both the motor cooling fan and the working fan operate onthe same shaft, in a bypass motor the chambers for the working air andmotor cooling air are separate and distinct from each other such thatmoisture laden air never enters the motor.

In the past, bypass motors have typically positioned a working air fanat an end of the motor/fan shaft, with the fan rotating within a fanshell, which is sometimes called a shroud. The shell defines a chamberwithin which the fan operates. An end of the fan shell is provided withan air intake, with the circumference or periphery of the shell beingdefined by a plurality of spaced apart exhaust apertures. The intakeaperture communicates with a vacuum chamber in the cleaning device,while the exhaust ports communicate with the ambient. Typically, the fanshell simply defines a chamber in which the fan rotates and,accordingly, that chamber becomes pressurized such that the air thereineventually finds its way to an exhaust port. However, with this type ofa structure, the fan operation is quite. inefficient.

Those skilled in the art will appreciate that previously known bypassmotors are highly inefficient. The pressurization of the fan chamber andthe indirect exhausting of the air therefrom gives rise to inherent airflow inefficiencies. Accordingly, there is a need in the art for ahighly efficient and quiet bypass motor for use in motor/fanapplications involving moisture laden air.

One attempt at improving bypass motors is disclosed in the U.S. patentapplication Ser. No. 09/072,035, entitled “Bypass Motor/Fan AssemblyHaving Separate Working Air Passages,” which is assigned to the Assigneeof the present invention and incorporated herein by reference. Thisapplication discloses a fan end bracket, positioned below a bottomsurface of the working air fan in such a way that the working air ismoved out and down through separate and distinct exhaust apertures thatare aligned with exhaust ports of the fan shell or shroud. Although thisis an improvement over previously known bypass motor/fan assemblies,turbulence still occurs. Accordingly, there is still a need in the artfor improvement in the efficiency of a bypass motor for use in motor/fanapplications.

DISCLOSURE OF INVENTION

In light of the foregoing, it is a first aspect of the present inventionto present a bypass motor/fan assembly in which the working air isexhausted through gradually expanding vanes of uniform cross-section,thereby increasing efficiency.

Another aspect of the present invention is the provision of a bypassmotor/fan assembly in which the working air fan is maintained in a fancavity formed by the vanes of a fan end bracket and in which theplurality of vanes are positioned in close proximity to the exhaustports of the working air fan.

Yet another aspect of the present invention is to provide a bypassmotor/fan assembly, as set forth above, in which a channel formedbetween the vanes gradually expands which, in turn, places exhaust airin an annular gathering chamber and then out through the exhaustapertures of a fan shroud.

A further aspect of the present invention is to provide a bypassmotor/fan assembly, wherein the fan shroud provides a logarithmic-shapeddischarge area that gradually increases in size until tangentiallyexhausted.

Still another aspect of the present invention is to provide a bypassmotor/fan assembly, as set forth above, in which an interior surface ofthe fan shroud contacts at least a portion of each vane's top edge.

Still yet another aspect of the present invention is to provide a bypassmotor/fan assembly, as set forth above, in which an air intake seal isdisposed between the shroud and the working air fan to directlytransition inflowing air into the working air fan.

The foregoing and other aspects of the present invention, which shallbecome apparent as the detailed description proceeds, are achieved by abypass motor assembly, comprising a motor having a rotatable shaft, aworking air fan secured to the rotatable shaft, a shroud having anintake eyelet and at least one exhaust aperture, an end bracket having ashaft hole through which the shaft extends, the end bracket and theshroud partially enclosing the working air fan, wherein rotation of theworking air fan draws air in through the intake eyelet and exhausts theair through at least one exhaust aperture, and the end bracket having aplurality of vanes that form a fan chamber that receives the working airfan such that air expelled by the working air fan is re-directed by thevanes toward at least one exhaust aperture.

Other aspects of the present invention are attained by a bracket for abypass motor assembly which includes a tapered working fan rotated by amotor shaft, wherein the tapered working fan is partially enclosedbetween a shroud and the bracket, the bracket comprising a base having aperiphery, a shoulder extending from the periphery, and a plurality ofvanes extending from the shoulder, the plurality of vanes facilitatingmovement of air expelled by the tapered working fan out the shroud.

Still another object of the present invention is attained by a motorizedfan assembly, comprising an end bracket with a rotatable shafttherethrough, a shroud having an intake eyelet and a plurality ofexhaust apertures, the shroud enclosing the end bracket, a fan connectedto the rotatable shaft, and rotatably received between the end bracketand the shroud, and an air intake seal disposed between the shroud andthe fan.

These and other objects of the present invention, as well as theadvantages thereof over existing prior art forms, which will becomeapparent from the description to follow, are accomplished by theimprovements hereinafter described and claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

For a complete understanding of the objects, techniques and structure ofthe invention reference should be made to the following detaileddescription and accompanying drawings wherein:

FIG. 1 is an elevational view illustrating an assembly comprised of afan and housing configuration in accordance with the present inventionas these may be mounted to an electric motor, the motor being shown viaghost lines for the purposes of the illustration;

FIG. 2 is an elevational view, partially broken away, of the fan/housingassembly as these may be mounted to a motor shaft;

FIG. 3 is an elevational view of a fan shroud with a portion thereofbeing continued via ghost-line showing;

FIG. 4 is a rear elevational view of a fan shroud, a working air fan,and an end bracket;

FIG. 5 is an enlarged sectional view of the fan housing as may be takenat line 5—5 of FIG. 3 illustrating a first configuration for an airintake seal;

FIG. 6 is a plan view of another embodiment for an air intake seal asmay be applied to the fan housing shown in FIG. 3;

FIG. 7 is an enlarged sectional view similar to FIG. 5 showing the boreseal of FIG. 6 mounted to the fan housing;

FIG. 8 is an enlarged sectional view of another embodiment for an airintake seal;

FIG. 9 is a plan view of the seal embodiment shown in FIG. 8; and

FIG. 10 is an elevational view of a tangential bypass motor/fan assemblywith a covering shroud partially broken away.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now to the drawings and, more particularly, to FIGS. 1-4, itcan be seen that a bypass motor/fan assembly made in accordance with theinvention is designated generally by the numeral 10. The assembly 10includes a motor housing 12 that carries an electrical motor whichreceives power and rotates a shaft 14 as is well known in the art. Aplurality of standoffs 16 are disposed around the periphery of the motorhousing 12 to support a working air fan assembly, designated generallyby the numeral 20. The standoffs 16 form a gap 22 between the workingair fan assembly 20 and the housing 12 so as to allow cooling air to bedrawn through the motor housing 12.

The working air fan assembly 20 has three major components: a diffuserend bracket, designated generally by the numeral 24; a fan 26; and ashroud, designated generally by the numeral 28. The shaft 14 extendsthrough the diffuser end bracket 24 and is connected to the fan 26. Theshroud 28, along with the end bracket 24, partially encloses the fan 26.The shroud 28 provides a working air intake eyelet 30 which is centrallydisposed so that working air is axially drawn into the fan 26 which thenradially moves the working air.

The end bracket 24 includes a lip 34 which forms an outer rim 36. Asloping shoulder 38 curvilinearly extends from the outer rim 36 to aninner rim 40. Centrally disposed within the inner rim 40 is a base 42.Extending through the base 42 is a bearing/shaft hole 48 which receivesa bearing sleeve 50 within which the shaft 14 is journaled.

A plurality of vanes 52 radially and curvilinearly extend from the innerrim 40 and along a substantial portion of the sloping shoulder 38. Eachvane has a top edge 54 that follows the shape of the shoulder 38. Inother words, the height of the top edge 54, with respect to the shoulder38, remains substantially the same. Each vane has a leading end 56proximal the inner rim and a trailing end 58 proximal the outer rim 36.Each vane has a fillet 60 which provides a smooth transition between thevane 52 and the shoulder 38. Adjacent vanes 52 form a channel 64therebetween which gradually expands the working air flow from the innerrim toward the outer rim. Between the trailing ends 58 and the outer rim36, a gathering chamber 68 is formed when the shroud 20 is secured tothe end bracket 24. It will be appreciated that a periphery formed bythe trailing ends 58 is positioned at about a mid-point between theouter diameter of the working air fan 26 and the inner diameter of theshroud 28 when affixed to the bracket 24. The leading ends 56, alongwith the base 42 and the inner rim 40, form a fan chamber 46 that issized to receive the outer periphery of the fan 26. The vanes 58tangentially fan out from the fan chamber 46 to the gathering chamber68.

The working air fan 26 includes a flat disc 76 and a tapered disc 78.The discs 76 and 78 are connected to one another by a plurality ofcurvilinear fan vanes 80, as is well known in the art. The tapered disc78 has a fan eye hole 82 which is aligned with the intake eyelet 30. Thefan vanes 80, along with the outer periphery of the discs 76 and 78,form fan exhaust ports 84 which are equally distributed about theperiphery of the fan 26. Collectively, the ports 84 can be referred toas an exhaust region 86. The fan 26 is attached to the shaft 14 by awasher 88, which bears against the flat disc 76, and a nut 90.

The shroud 28 is generally cup-shaped and includes a tapered plate 94with a downwardly extending sidewall 96. The shroud 28 is press-fit ontothe end bracket 24. Of course, fasteners and the like could be used.When assembled, the tapered plate 94 and the tapered disc 78 form a gap97 therebetween. The sidewall 96 provides a plurality of shroud ports 98which are oriented in the same curvilinear direction as the vanes. Theunderside of the tapered plate 94 is placed in close, touching contactwith the top edges 54 at least at their respective leading ends 56.Accordingly, at least a portion of each channel 64 is a fully enclosedpassage way. With the foregoing construction, the discharge area orgathering chamber 68 is of a volumetric proportion slightly greater thanthe outlet discharge area of the guide vanes 58. The vanes 58 end in aradial form, as does the fan 26 and the shroud 28. As the working air isexhausted from the fan 26, it has radial and straight components thatmove axially toward the outer rim 36 in a series of annular rings towardthe shroud ports 98. These “annular rings” of air are then sequentiallyexhausted through the ports 98.

Although not wanting to be bound by theory, it is believed that theleading ends 56 do about 95% of the work in moving the air toward theports 98. The configuration of the vanes past the leading ends is lesscritical, although it is desirable that they provide an unimpeded,orderly discharge.

Referring now to FIG. 5, it can be seen that an air intake seal isdesignated generally by the numeral 100. In one embodiment, shown inFIG. 5, the seal 100 includes a collar 102 which is attached to theshroud 28 by a plurality of rivets 104. The collar, which is preferablymade of nylon, provides an outer flange 106 which is attached to theunderside of the shroud around the inlet 30. Extending from the flangeis a flat portion 108. And extending downwardly from the flat portion108 is a finger 110 which is virtually in contacting relationship withthe tapered disc 78 of the working air fan 26. Upon assembly, the collaris “burned in” so that the finger 110 is in as close a relationship withthe eye hole 82 as possible. As such, the fan freely rotates about thefinger, but the gap between the finger and the fan disc 78 is deminimis.

Alternatively, as shown in FIGS. 6-7, the air intake seal 100 mayutilize a shroud inner surface 114 with a seal ring 116 attachedthereto. The seal ring 116 is provided with an adhesive material 118that is exposed by removing a liner 120. The adhesive portion is thenpressed upon the shroud inner surface 114. As can be seen, the ring 116has an inner diameter substantially equal to the inner diameter of theinlet 30. In the preferred embodiment, the seal ring 116 is made fromexpanded polytetrafluoroethylene, manufactured by Gore-Tex, Inc.

In another alternative, as shown in FIGS. 8 and 9, the air intake seal100 may utilize the shroud inner surface 114 and a retaining ring 130.The ring 130 is larger in diameter than the eyelet 30 and has a flange132 that is connected to the shroud 28, preferably by spot welding. Aseal strip 134, which is an extruded length of expandedpolytetrafluoroethylene, is cut to a length equal to a diameter aroundthe eyelet 30. The strip 134 is positioned between the flange 132 andthe eyelet 30. It will be appreciated that a lip 136 extends around theeyelet as a result of its formation. The seal strip 134 snugly fitsbetween the lip 136 and the flange 132. To hold the strip in place,detents 138 are staked about the flange 132. The strip is of a size toat least frictionally engage the fan disc 78.

In all these embodiments, the seal 100 significantly reduces or closesthe gap 97 provided between the tapered disc 78 and the inner surface114. In other words, the seal 100 minimizes entry of working air intothe gap 97.

Operation of the assembly 10 will now be described. Generally, the motorwithin the motor housing 12 is energized and rotates the shaft 14. This,in turn, rotates the fan 26 and working air is drawn through the fanassembly 20. Features contained in the working air fan assembly 20 whichgreatly enhance the flow-through of the working air include the airintake seal 100. The alignment of the intake eyelet 30 and the faneyehole 82 is such that air is normally drawn into the area between thediscs 76 and 78. To minimize the turbulence in the shroud and, inparticular, between the tapered disc 78 and the interior surface of theshroud inner surface 114, the intake seal 100 precludes direct entry ofworking air into this area. Accordingly, a significant portion of theworking air is drawn through the fan 26 and not diverted to the areabetween the fan and the shroud. As the fan rotates, the working air iscaptured by the fan vanes 80 and exhausted out the exhaust ports 84 inthe exhaust region 86.

Another significant feature of the present invention is that theplurality of vanes 52, along with the inner rim 40 and the base 42, forma fan chamber 46 in which the fan 26 rotates. The leading ends 56 of thevanes 52 are disposed closely about the outer periphery of the fan 26around the exhaust region 86. Indeed, each vane 52 has a top edge 54which is of such a height so as to be equivalent to or larger than theheight of the exhaust region 86. Accordingly, almost as soon as theworking air is expelled from the fan exhaust ports 84, it is deflectedand captured by the leading ends 56 and received in the channels 64formed by the adjacent vanes 52 and the shroud 94. Since the channelsare covered by the underside of the shroud 28 for at least a portion oftheir length, the momentum of the working air is substantiallymaintained. The working air is then gradually expanded and directedoutwardly and downwardly along the sloping shoulder 38. At the trailingends 58 of the vanes 52, which are of equivalent radial distance, theworking air is deposited into the annular gathering chamber 68. The aircirculates downwardly around the chamber 68 and becomes pressurized andthen exits the shroud 28 through the shroud ports 98.

Referring now to FIG. 10, a variation of the inventive concept may beemployed with a tangential discharge bypass motor/fan assembly,designated generally by the numeral 210. The assembly 210 incorporatesmany of the same structural features of the assembly 10, including, butnot limited to, a fan end bracket 212 which has a plurality ofcurvilinear vanes 214. As in the other embodiment, one end of the vanes214 are closely positioned about the outer periphery of the fan 26. Anouter periphery of the end bracket 212 is logarithmically shaped andincreasing in size from an initial discharge area 218 through agradually expanding discharge area 219 to a tangential exhaust port 220.A form-fitting fan shell 221 having an axial inlet fits over the endbracket 212. As in the other embodiment, the inner surface of the shell221 contacts at least a portion of each vane's top edge. As such, thechannels between the vanes 214 are partially enclosed near the fan outerperiphery. This greatly assists in maintaining the momentum of theworking air after it exits the fan.

The logarithmically-shaped discharge area gradually increases from thevanes furthest away from the exhaust port to the vanes nearest theexhaust port. For example, the outlet area (the volume between the guidevanes furthest from the port 220) plus about 5% of that area yields thedischarge area 218. The outlet area of subsequent adjacent guide vanedischarges (plus about 5%) is added to the previous area to form thelogarithmic shape. This configuration greatly assists in efficientlymoving the working air toward the port 220. The assembly 210 operatesalmost identically as the assembly 10 except for the tangentialdischarge. The assembly 210 can be provided with any of the air intakeseal embodiments disclosed for use with the assembly 10.

Based upon the foregoing description, the advantages of the presentinvention are readily apparent. In particular, the amount of turbulenceand extraneous airflow which interferes with the working air flowingthrough the assemblies 10, 210 is significantly reduced. In particular,the working air is moved directly from the fan to a radial diffuserarea/gathering chamber that unloads the pressure caused by the fan. Theair then gradually slows down and is circulated into the gatheringchamber 68 and then is efficiently maneuvered out of the shroud 28. Ithas been determined that the air loses a significant amount of drivingforce once it leaves the apertures. Accordingly, to minimize turbulenceand increase efficiency, it has been determined it is much moreeffective to immediately capture the working air via the vanes as it isgenerated by the fan. This air is then gently expanded and its pressurereduced in the gathering chamber to collectively force the air out fromthe shroud ports. Whereas most prior art fans provide an operatingefficiency anywhere from between 27-37% efficiency, this new design hasbeen shown to have at least about 50% efficiency. Efficiency, as used inthis context, is a factor of motor efficiency and blower efficiency,wherein it has been determined that turbulence/interference within thefan shroud greatly diminishes the airflow therethrough which causes themotor to work harder and generate heat and losses in the system. In thepresent invention, the losses are significantly reduced to provide alonger-lasting motor assembly and other tangible benefits.

Thus it can be seen that the objects of the invention have beensatisfied by the structure presented above. While in accordance with thepatent statutes only the best mode and preferred embodiment of theinvention has been presented and described in detail, it is to beunderstood that the invention is not limited thereto or thereby.Accordingly, for an appreciation of the true scope and breadth of theinvention reference should be made to the following claims.

What is claimed is:
 1. A bypass motor assembly, comprising: a motorhaving a rotatable shaft; a working air fan secured to said rotatableshaft, said working air fan having an outer periphery exhaust region; ashroud having an intake eyelet and at least one exhaust aperture; an endbracket having a shaft hole through which said shaft extends, said endbracket and said shroud partially enclosing said working air fan,wherein rotation of said working air fan draws air in through saidintake eyelet and exhausts the air through said at least one exhaustaperture; and said end bracket having a plurality of vanes that form afan chamber that receives said working air fan wherein said plurality ofvanes are closely disposed about said outer periphery exhaust regionsuch that air expelled by said working air fan is re-directed by saidvanes toward said at least one exhaust aperture.
 2. The assemblyaccording to claim 1, further comprising: an air intake seal disposedbetween said shroud and said working air fan.
 3. The assembly accordingto claim 2, wherein said working air fan has an eye hole aligned withsaid intake eyelet, and wherein said air intake seal is positioned so asto maximize the flow of working air from said intake eyelet to said faneye hole.
 4. The assembly according to claim 3, wherein said air intakeseal comprises a collar secured around said intake eyelet, said collarhaving a finger that extends into said fan eye hole.
 5. The assemblyaccording to claim 3, wherein said air intake seal comprises a seal ringsecured to an underside of said shroud and around said intake eyelet,said seal ring minimizing a gap between said shroud underside and saidworking air fan.
 6. The assembly according to claim 5, wherein said sealring is expanded polytetrafluoroethylene.
 7. The assembly according toclaim 3, wherein said air intake seal comprises a seal strip carried byan underside of said shroud around said intake eyelet.
 8. The assemblyaccording to claim 1, wherein each said vane has a leading end and atrailing end.
 9. The assembly according to claim 1, wherein said shroudhas a plurality of exhaust ports distributed about said shroud.
 10. Abypass motor assembly, comprising: a motor having a rotatable shaft; aworking air fan secured to said rotatable shaft; a shroud having anintake eyelet and at least one exhaust aperture; an end bracket having ashaft hole through which said shaft extends, said end bracket and saidshroud partially enclosing said working air fan, wherein rotation ofsaid working air fan draws air in through said intake eyelet andexhausts the air through said at least one exhaust aperture; said endbracket having a plurality of vanes that form a fan chamber thatreceives said working air fan such that air expelled by said working airfan is re-directed by said vanes toward said at least one exhaustaperture; and wherein said end bracket has a sloping shoulder such thatsaid vanes slope in a corresponding manner.
 11. A bypass motor assembly,comprising: a motor having a rotatable shaft; a working air fan securedto said rotatable shaft; a shroud having an intake eyelet and at leastone exhaust aperture; an end bracket having a shaft hole through whichsaid shaft extends, said end bracket and said shroud partially enclosingsaid working air fan, wherein rotation of said working air fan draws airin through said intake eyelet and exhausts the air through said at leastone exhaust aperture; said end bracket having a plurality of vanes thatform a fan chamber that receives said working air fan such that airexpelled by said working air fan is re-directed by said vanes towardsaid at least one exhaust aperture; and wherein said end bracket has adownwardly sloping shoulder and each said vane has a trailing endextending radially along said sloping shoulder, said trailing ends andsaid shroud forming a gathering chamber therebetween where the workingair collects prior to exiting from said at least one exhaust aperture.12. A bypass motor assembly, comprising: a motor having a rotatableshaft; a working air fan secured to said rotatable shaft; a shroudhaving an intake eyelet and at least one exhaust aperture; an endbracket having a shaft hole through which said shaft extends, said endbracket and said shroud partially enclosing said working air fan,wherein rotation of said working air fan draws air in through saidintake eyelet and exhausts the air through said at least one exhaustaperture; said end bracket having a plurality of vanes that form a fanchamber that receives said working air fan such that air expelled bysaid working air fan is re-directed by said vanes toward said at leastone exhaust aperture; and wherein said end bracket has a downwardlysloping shoulder and wherein each said vane has a leading end and atrailing end.
 13. A bypass motor assembly, comprising: a motor having arotatable shaft; a working air fan secured to said rotatable shaft; ashroud having an intake eyelet and at least one exhaust aperture; an endbracket having a shaft hole through which said shaft extends, said endbracket and said shroud partially enclosing said working air fan,wherein rotation of said working air fan draws air in through saidintake eyelet and exhausts the air through said at least one exhaustaperture; said end bracket having a plurality of vanes that form a fanchamber that receives said working air fan such that air expelled bysaid working air fan is re-directed by said vanes toward said at leastone exhaust aperture; and wherein each said vane has a top edgeextending between a leading end to a trailing end, and wherein saidshroud is in touching contact with at least a portion of said top edges.14. A bypass motor assembly, comprising: a motor having a rotatableshaft; a working air fan secured to said rotatable shaft; a shroudhaving an intake eyelet and at least one exhaust aperture; an endbracket having a shaft hole through which said shaft extends, said endbracket and said shroud partially enclosing said working air fan,wherein rotation of said working air fan draws air in through saidintake eyelet and exhausts the air through said at least one exhaustaperture; said end bracket having a plurality of vanes that form a fanchamber that receives said working air fan such that air expelled bysaid working air fan is re-directed by said vanes toward said at leastone exhaust aperture; wherein vanes adjacent each other form channelstherebetween; and wherein said shroud is in touching contact with eachsaid vane proximal said leading ends so as to enclose at least a portionof each said channel.
 15. A bypass motor assembly, comprising: a motorhaving a rotatable shaft; a working air fan secured to said rotatableshaft; a shroud having an intake eyelet and at least one exhaustaperture; an end bracket having a shaft hole through which said shaftextends, said end bracket and said shroud partially enclosing saidworking air fan, wherein rotation of said working air fan draws air inthrough said intake eyelet and exhausts the air through said at leastone exhaust aperture; said end bracket having a plurality of vanes thatform a fan chamber that receives said working air fan such that airexpelled by said working air fan is re-directed by said vanes towardsaid at least one exhaust aperture wherein said shroud has a singletangential exhaust aperture; and wherein said plurality of vanes eachhave a trailing end that with said shroud form a gathering chamber, saidgathering chamber logarithmically expanding toward said singletangential exhaust aperture.
 16. A bracket for a bypass motor assemblywhich includes a tapered working fan rotated by a motor shaft, whereinthe tapered working fan is partially enclosed between a shroud having atleast one vent and the bracket, the bracket comprising: a base having aperiphery that is adapted to be sealed by the shroud; a shoulderextending from said periphery; and a plurality of vanes extending fromsaid shoulder, said plurality of vanes facilitating movement of airexpelled by the tapered working fan out the vent.
 17. The bracketaccording to claim 16, further comprising: an outer rim surrounding saidshoulder and adapted to support the shroud, said plurality of vanesextending almost to said outer rim, each one of said plurality of vaneshaving a trailing end, said plurality of trailing ends and the supportedshroud defining a gathering chamber therebetween.
 18. The bracketaccording to claim 16, wherein each said plurality of vanes has aleading end proximal said periphery, said leading ends and said baseforming a fan chamber that receives the tapered working fan.
 19. Thebracket according to claim 16, wherein each said vane has a leading endand a trailing end and wherein said shoulder is downwardly sloping. 20.The bracket according to claim 19, wherein adjacent vanes form graduallyexpanding channels therebetween.
 21. A motorized fan assembly,comprising: an end bracket with a rotatable shaft therethrough; a shroudhaving an intake eyelet and at least one exhaust aperture, said shroudenclosing said end bracket; a fan connected to said rotatable shaft, androtatably received between said end bracket and said shroud; and an airintake seal disposed between said shroud and said fan, wherein said airintake seal comprises a seal strip secured to an underside of saidshroud around said intake eyelet.
 22. The assembly according to claim21, wherein said working air fan has a fan eye hole aligned with saidintake eyelet, said air intake seal is positioned so as to maximize theflow of working air from said intake eyelet to said fan eye hole. 23.The assembly according to claim 22, wherein said seal strip is expandedpolytetrafluoroethylene.
 24. The assembly according to claim 21, furthercomprising an indented flange for holding said seal strip.